Chapter 1: Cell the Fundamental Units of Life Flashcards
Cells vary enormously in _______ and _______.
Appearance and Function
Living Cells All Have a Similar ________.
Basic Chemistry
(True or False) Cells resemble one another to an astonishing degree in the details of their chemistry.
True
(true or false) In all organisms, genetic information—in the form of genes—is carried in DNA molecules.
true
Long polymer chains of DNA
are made from the same set of four monomers, called _________.
nucleotides
The information encoded in these DNA molecules is read out, or transcribed, into a related set of polynucleotides called _____.
RNA
The flow of information—from DNA to RNA to protein—is called ______.
central dogma
Proteins are built from _______.
amino acids
Living Cells Are ______ Collections of Catalysts
Self-Replicating
(true or false) All living organisms are constructed from cells.
True
(true or false) Life is an autocatalytic
process.
true
The process by which living species become gradually modified and adapted to their environment in more and more sophisticated ways.
evolution
The entire sequence of nucleotides in an organism’s DNA.
Genome
(true or false) Different cells express different genes.
True
He examined a piece of cork and in 1665 reported to the Royal Society of London that the cork was composed of a mass of minute chambers.
Robert Hooke
Who documented the results of a systematic investigation of plant and animal tissues with the light microscope, showing that cells were the universal building blocks of all living tissues?
Matthias Schleiden and Theodor Schwann
All living cells are formed by the growth and division of existing cells—a principle
sometimes referred to as the ______.
cell theory
A dense material often made of protein fibers embedded in a gel of long sugar chains.
an extracellular matrix
Each cell is typically about _______ in diameter.
5–20 μm
(true or false) All of the internal
structures of a cell can be seen with a
light microscope.
False - some
Microscopes that use sophisticated methods of illumination and electronic image processing to see fluorescently labeled cell components in much finer detail.
fluorescence microscopes
The most recent super-resolution fluorescence microscopes, for example, can
push the limits of resolution down even further, to about ______ (nm).
20 nanometers
Microscopes that can reveal details down to a few nanometers. It has the highest magnification and best resolution.
electron microscope
The type of electron microscope used to look at thin sections of tissue is known as
transmission electron microscope
This instrument transmits a beam of electrons rather than a beam of light through the sample.
transmission electron microscope.
Another type of electron microscope that scatters electrons off the surface of the sample and so is used to look at the surface detail of cells and other structures.
Scanning electron microscope
Organisms whose cells have a nucleus are called ______.
eukaryotes
Eukaryote - “eu” means _____ and “karyon” means _____.
eu - well or truly
karyon - kernel or nucleus
Organisms whose cells do not have a nucleus are called ______.
prokaryotes
prokaryotes - “pro” means ____.
before
are typically spherical, rodlike, or corkscrew-shaped.
Prokaryotes
The bacterium ______ has served as an important model organism.
Escherichia coli (E. coli)
(true or false) Some bacteria are photosynthetic.
true
The World of Prokaryotes Is Divided into Two Domains:
Bacteria and Archaea
(true or false) Yeasts are simple, free-
living eukaryotes.
True
usually the most prominent organelle in a eukaryotic cell
nucleus
are present in essentially all eukaryotic cells, and they are among the most conspicuous organelles in the cytoplasm
mitochondria
What kind of relationship is evident in which the host eukaryote and the engulfed bacterium helped each other to survive and reproduce?
symbiotic relationship
are large, green organelles that are found in the cells of plants and algae, but not in the cells of animals or fungi.
Chloroplasts
(true or false)
Mitochondria are thought to have evolved from engulfed bacteria.
an irregular maze of interconnected spaces enclosed by a membrane
endoplasmic reticulum (ER)
It is the site where most cell-membrane components, as well as materials destined for export from the cell, are made.
endoplasmic reticulum (ER)
Stacks of flattened, membrane-enclosed sacs constitute the ______.
Golgi apparatus
are small, irregularly shaped organelles in which intracellular digestion occurs, releasing nutrients from ingested food particles into the cytosol and break down unwanted molecules for either recycling within the cell or excretion from the cell.
lysosomes
are small, membrane-enclosed vesicles that provide a sequestered environment for a variety of reactions in which hydrogen peroxide is used to inactivate toxic molecules.
peroxisomes
Animal cells can engulf very large particles, or even entire foreign cells, by ______.
endocytosis
In the reverse process, called _______, vesicles from inside the cell fuse with the plasma membrane and release their contents into the external medium.
exocytosis
the part of the cytoplasm that is not contained within intracellular membranes.
cytosol
(true or false) Eukaryotic cells engage in
continual endocytosis and exocytosis
across their plasma membrane.
true
(true or false) The cytosol is uncrowded.
false - extremely crowded
(true or false) In a multicellular organism, there is no division of labor among cells.
false - there is division
(true or false) Only living cells can self replicate.
true
(true or false) Viruses have the ability to reproduce by their own efforts.
false - do not have the ability
All living things have apparently evolved from the same ______.
ancestral cell
______ are mistakes in the DNA that change the genetic plan from that of the previous generation.
Mutations
It is estimated that cells existed between ______.
3.5 — 3.8 billion years ago.
(mm) visible with unaided eye.
0.2 mm
light microscope
200 nm
super-resolution fluorescence microscope
20 nm
electron microscope
0.2 nm
A specialized type of fluorescence microscope that builds up an image by scanning the specimen with a laser beam.
confocal fluorescence microscope
generators of chemical energy for the cell.
mitochondria
the basic chemical fuel that powers most of the cell’s activities.
ATP - adenosine triphosphate
process of consuming oxygen and releasing CO2.
cell respiration
ferry materials berween one membrane-closed organelle and another.
transport vesicles
The cytoskeleton is composed of three major filament types:
actin filaments, microtubules, intermediate filaments
eukaryotic cells are typically ___ times the length and ____ times the volume of prokaryotic cells.
10 x length
1000 x volume
a class of free-living, motile, unicellular organisms
protozoans
the acquisition of mitochondria by the engulfment of ______.
aerobic bacteria
the acquisition of chloroplasts by the engulfment of _____.
photosynthetic bacteria
(functions) carry out the final oxidation of food molecules and produce ATP.
mitochondria
(function) synthesize complex molecules for export from the cell and for insertion in cell membranes
endoplasmic reticulum and golgi apparatus
(function) digest large molecules
lysosomes
a highly concentrated mixture of large and small molecules that carry out many essential biochemical processes
cytosol
composed of protein filaments that extend throughout the cytoplasm and are responsible for cell shape and movement and for the transport of organelles and large molecular complexes drom one intracellular location to another.
cytoskeleton
model organisms:
Escherichia Coli (bacterium)
Saccharomyces Cerevisiae (brewer’s yeast)
Arabidopsis (plant)
Drosophila Melanogaster (fruit fly)
Caenorhabditis (nematode)
Fish
Mouse
Human
The human genome has about _____ coding genes.
19,000
